5. Joe Louis

Heavyweight Joe Louis is best known for his dynamic skills in the ring and the quality of his opponents. Louis held the heavyweight championship title for over 11 years and fought 27 championship fights at that level, a record still unbroken.

Louis became the first boxer to defeat six heavyweight champions. Among his most famous opponents were Jim Braddock, Primo Carnera, Max Baer, and Rocky Marciano.

Memorable bout: On June 22, 1938, Joe Louis, the World Heavyweight Champion at the time, knocked out the challenger, Max Schmeling, in the first round. This fight cemented his popularity as one of the greatest champions of all time.

Pound-for-pound matchup: Muhammad Ali This would be a dream match for many reasons. Both these fighters had excellent hand speed. Joe Louis would have power on his side but Ali was able to take hard hits throughout his career. Accuracy and rhythm would be the determining factor in this fight.